Cushioning mechanism



Aug. 21, l95 H. sPENcE 2954977?.

CUSHIONING MECHANISM 2 Slfleets-Sheee:l 1

Filed May 9, 1947 i .By

ATTRNEY ug.2l, 1951 H, SPENCE 2,564,771

CUSHIONING MECHANISM l Filed May 9, 1947 v 2 -Sheets-Sheet 2 T l INVENToR. ,"1 ,f/ 5 Hubert Lfpe c BY R40 l A W 40 34 ATTURNEY latented ug. 211, 1951 cUsHloNING MECHANIsM Hubert L. Spence, East Cleveland, Ohio, assigner rto National Malleable and Steel Castings Company, Cleveland, Ohio, a corporation of Ohio..

Application May 9, 1947, Serial N o. 7417,0*13

This invention relates to cushioning mechanism particularly adaptable for use in railway vehicles.

An object of my invention is to provide a cushioning mechanism in which a portion of the resilient means thereof in addition to cushioning shocks also serves tov actuate friction generating members of the mechanism.

Another object is to provide a cushioning mechanism in which soft initial action is provided, followed by the actuation of friction generating members to absorb heavy shocks.

A further object is to provide a cushioning mechanism in which rubber means is utilized to provide soft initial action and to actuate friction members during the remainder of the travel of the mechanism.

A still further object is to provide a cushioning mechanism in which wedge-shaped friction shoes are actuated by rubber means after a predetermined amount of compression of the rubber.

A more specific object is to provides. cushioning mechanism having a friction member. friction shoes slidably associated with the member, spring means for resisting relative movement between the member and shoes, a follower for actuating the shoes, and rubber means interposed between the follower and shoes adaptedv Fig. 1 is a plan view partly insection of an embodiment of my invention.

Fig. 2 is an elevational view partly in section, taken along line 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view taken along line 3-3 of Fig. 1.

Fig. 4 is a partialview taken along line 4-4 of Fig. 1.

Fig. 5 is a plan view of the friction member of the mechanism. y I

' Fig. 6 is an elevational view of the Vfriction member.

Fig. '7 is an end View of the friction member.

Fig. 8 is a plan view of one of the friction shoes of the mechanism.

Fig. 9 is an elevational view of the friction shoe.

Fig. 10 is an end view of the friction shoe.

My invention in its general arrangement comprises a friction member I0, wedge-shaped friction shoes I2 slidably associated withy member 17 Claims. (Cl. 267-1) 2 Il), spring means I4 for opposing movement of shoes I2 relative to memberll), a seat member I6 interposed between shoes I2 and spring means I4, a follower member I8, resilient cushion units 2D interposed between the follower I8 and shoes I2, and tie bolts 22.

Friction member I0 is formed with a-base or follower portion 24, which has a longitudinally extending friction portion 25. Portion 25 is preferably formed with two pairs of inwardly converging longitudinally extending friction surfaces 26. These surfaces diverge slightly in a direction toward base 24, as may be seen in Figs. 1 and 7, to increase the friction-generated. as shoes I2 move alongportion 25, during actuation of the mechanism. Shoes I2 slidably engage surfaces 26 and are adapted to move lengthwise thereof l against the resistance of spring means I4. The `shoes are provided on. their inner sides with pairs of friction surfaces 28 which are angularly disposed to correspond with surfaces 26. Spring means I4'preferably comprise two sets of inner and outer coil springs, each set being positioned adjacent-friction portion 25 and in engagement with base 24. Engaging the other end of springs I4 is seat member I6 which has a fiat base portion 30 for engagement with shoes I2. Portion 30 has a central opening 3| to permit the seat to move lengthwise of friction portion 25 during compression and release of the cushioning mechanism. rSeat I6 also has peripheral flangesL 32 which serve to strengthen the member and to maintain springs I4 in assembled relation. Each shoe I2 on its outer side is provided with a plane sloping surface 34 and with the two shoes in assembled relation, these surfaces are so disposed as to converge toward the end of the mechanism.

Follower I8 comprises a chambered portion having V-shaped Walls 36 which correspond in slope with walls 34 of the shoes. Interposed between shoes I2 and follower I8 and in engagement with walls 34 and 36 thereof, respectively, are cushion units 2U. The cushion units comprise a pad or block 31 of resilient material such as rubber with plates 38 vulcanized or otherwise bonded to the sides thereof. In order to prevent the cushioning units from sliding relative to shoes I2 or follower I8 during compression of the units, shoulders 40 and 4I on the shoes and follower, respectively, are provided for engagement with plates 38. Movement of the cushion units laterally of the mechanism is limited by shoulders 39 on followerk I8 which are adapted to engage the adjacent plate 328. Tie

walls 42 serve to reinforce follower I8 and prevent walls 36 from spreading when a compressive force is applied to the mechanism. An abutment 43 is provided on the follower and is adapted for engagement with end surface 48 of friction portion 25 to take the over-solid blows and limit the travel of the mechanism.

Springs I4 are held underinitial compression by means of integral lugs 44 on friction portion 25 which engage stops 45 on shoes I2. It will be understood that the amount of initial compression of springs I4 may be varied by forming lugs 44 closer or farther from base 274 of the friction member. Follower I8 and cushion units 20 are held in assembled relation with the rest of the mechanism by means of tie bolts 2 2 which connect the follower to friction" member I0. Base portion 24 of the friction member is recessed on each side thereof as "at 46 to allow the bolts to slide during compression of the mechanism in service and in no "way interfere with the operation. By means of nutsm4'l the cushion units may be placed under. the. desiii, amount f initial compression. Movement o f follower' I8 relative to the shoes during compression of the mechanism is limited by the engagement of surfaces 58 of wall 42 with surface 5I on shoes I2, therebyl precluding any, damage to the cushion units vby overloading them.

The operation of the mechanism is as follows:

Assuming for the purpose of illustration that base 24 is held stationary and a longitudinal force is applied to` the-.end of follower I8, the initial movement thereof toward base 2 4 of the friction member is, resisted by the cushioning units 2i! which act in combined compression and shear, caused bythe relative movement of plates 38 toward' each other as Well as in a lengthwise direction. p

In order to provide room for the flow of the rubber 'as it is being compressed, spaces 54 extending laterally alongthe inner ends of blocks 31 and spaces 55 extending along the sides of the locks are provided in follower I8. It will be obiserved that the sides and ends of the rubber have been undercut slightly, to preserve the bond between the rubber4 andy the plates when rubber is compressed and toallowA greater space for expansion of the rubber withinrfollower I8. As follower I8 continues its. movement relative to the shoes it is resisted by the. rubber until surfaces 5I)A have engaged surfaces 5 I on the shoes, further compression andshear of the rubber being prevented to protect itfrom damage.

. During-the aforementioned movementof follower I.8 relative to the shoes, the initial compression of springs, I4has,been sufficient to maintain follower I6 as1 WellA as the shoes stationary. However, duringthe movement of follower I8 toward base 24, after engagement occurs between surfaces 5U and 5,.I furthermovement is resisted solely by springsY I,4 and the friction generated between shoes I2 andfriction portion 25. Thus, light forces and shocks are absorbed by the rubber units while the heavierblows are resisted by the coilsprings and frictional forces.

During the initial. movement of follower I8 relativeto shoes I2* cushion units 20 exert a lateral as well as longitudinal force against the shoes. Therefore the shoes Vare urged with increasing force into engagement with friction portion 25. during the initial vmovement of the follower. Aftersurfaces 50`land5l are in engagetogether as a unit the frictional force between 4 the shoes and portion 25, which has been built up to an appreciable amount, is immediately effective to oppose such further movement. In conjunction with springs I4 this frictional force Very effectively cushions any heavy forces applied to the mechanism. As previously noted surface 26 has a slight taper in a longitudinal direction so that a greater amount offriction is generated between the shoes and portion 25 than would occur if this surface were not tapered. As the shoes are urged lengthwise of portion 25 toward base 24 they are also forced laterally outwardly a small amount due to the wedging action whichfoccurs'between surfaces 26 and 28. This outward movement occurs against the resistance cf cushions which have already been com- -pressed a predetermined amount and against 'V'The cushioning of such shocks is done by the rubber units which possessy the resiliency necessary for this purpose. At the same time'the device has the required capacity to cushion the heavy shocks applied thereto.

' As described the operation of themechanism is such that'the preliminary 'travel is allowed only by lthe cushion units 2U`thereof While the balance of the travel is through spring means I4. `With this manner. of operation'the initial compression of springs I4 during assembly of the 'mechanism mustV be sufficient to permit'units 28 to'be compressed their predetermined amount before I springs I4 begin to compress. However itis tobe vunderstood'that the'initial compression of springs I4 and the resiliency of units 2ll`mayI be varied to obtain' various travel'characteristics. For example, the initial compression of'springs I4 could besuch that shoes I2 would begin to 'move lengthwise of portion 25 at some point before surfaces 5i] and 5I 'come into engagement as follower I8 compresses units 28; in its movement toward base 2 4, thus gradually/blending the'rubber' resistance in with the coil spring Vresistance'.

It is my purpose to provide substantial travel o f the mechanism in its operation. To attain this purpose I intend that the rubber orwhatever similar material is used in the'cu'shi'on units be of substantial thickness so as to iallow the rubber to cushion afconsiderabl'prtion of the 'force applied to the mechanism'.A For'instance.' a rubber cushion asthick a's @may b'e usedandthereby allow' as muchas 11/2" lori'gitudin'alV travel between follower I8 and shoes I2 withotverloadingvthe rubber. l

In assembling the mechanism lthe friction member I 0 i's placed'in any upright position, resting on base 24. Then springs I4n arefplaced in position and seat member I5 isap'pliedlA Next thev springs are compressed. af sufficient' 'amount by any suitable means" applied tom'ember I6 to provide sufficient clearance betweenvv base 3l!V and lugs 44 on friction portion 25. to enable shoes I2 to be slid'later'ally therebetween iri'to position in .en'gagementrf with portion25. YSprings I4. may

ment andthe shoes andsfollower begin to move the'rilbe'allowedytoexpandiintil limitedby the enshoes. Thereafter cushion units 20 may be added and follower I8 placed in position on the units.

The assembly is completed by the addition of tie bolts 22.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

What I claim is:

1. A cushioning mechanism comprising a friction member having a follower portion and a longitudinally extending friction portion, spring means adjacent said friction portion and having one end thereof in engagement with said follower portion, a seat member engaging the other end of said spring means and movable lengthwise of said friction portion, friction shoes engaging said seat member and slidably engaging said friction portion, stop means on said friction portion adapted upon assembly of the mechanism to engage said shoes to maintain said spring means under predetermined compression, follower means having sloped surfaces facing similarly sloped surfaces on said shoes, and resilient pads interposed between said sloped surfaces on saidv shoes and follower means adapted to be compressed to allow relative movement between said follower means and said shoes and to urge said shoes against said friction portion.

2. In a cushioning mechanism a friction member, friction shoes engaging said member and being slidable lengthwise thereof, spring means reacting between said member and said shoes for opposing movement of said shoes relative to said member, a follower member associated with said shoes movable relative to said shoes and lengthwise of said friction member, said follower member being adapted to urge said shoes against said friction member and also to urge said shoes lengthwise thereof, resilient pads interposed between said shoes and follower member, and stop means on said friction member, shoes, and follower member, part of said means comprising tie walls on said follower member adapted to engage said shoes to limit movement of said follower toward said shoes when said mechanism is compressed and other of said means comprising an abutment on said follower member facing the end of said friction member and being adapted to engage therewith for limiting movement of said follower member toward said friction member.

3. In a cushioning mechanism a friction member comprising a base portion and a longitudinally extending friction portion, said friction member having V-shaped friction surfaces, friction shoes having complementary V-shaped surfaces in engagement with said surfaces on said member, said shoes being adapted for movement lengthwise of said member, spring means reacting between said base portion and said shoes for opposing movement of said shoes, a follower member for said shoes having a pair of wedging surfaces, said shoes having surfaces which correspond in slope with said wedging surfaces, and rubber pads interposed between said surfaces on said shoes and follower member to allow relative movement between said shoes and follower member, said rubber pads being adapted to urge said l shoes longitudinally and laterally of said friction member in response to movement of said follower` member toward said shoes.

4. In a cushioning mechanism a pair of spaced followers, one of said followers having a centrally disposed friction portion extending toward said other follower, friction shoes slidably associated with the outer sides of said portion, spring means interposed between said shoes and said rstnamed follower for resisting movement of said shoes toward said first-named follower, said shoes and said other follower having opposed correspondingly sloped wedging surfaces, and rubber means interposed between said wedging surfaces, said rubber means being adapted to resist movement of said other follower relative to said shoes and to exert a lateral force on saidshoes.

5. A cushioning mechanism comprising a friction member having angularly disposed longitudinally extending friction surfaces, vfriction shoes having surfaces in engagement with said surfaces on said member and being adapted for movement lengthwise of said member, spring means reacting between said shoes and friction, member for opposing said movement of said.

shoes, said shoes having wedging surfaces on the outer sides thereof, rubber pads engaging said wedging surfaces for urging said shoes into en gagement with said friction member, and follower means having wedging surfaces corresponding in, slope with said wedging surfaces on said shoes,

and engaging said rubber pads.

6. A cushioning mechanism comprising a pair' of relatively movable end followers, one of said.

followers having a longitudinally extending friction portion, friction shoes slidably engaging said friction portion, spring means between said fric-y tion portion follower and said shoes for opposingv movement'ofY said shoes relative to said frictionv portion, said shoes having wedging surfaces on, the outer sides thereof, said other follower hav-y ing a recessed portion provided with wedging sur-l faces corresponding with wedging surfaces on'4 said shoes, and rubber means within said recessedportion and interposed between said wedging sur-- lfaces on said shoes and follower, said rubber means upon relative movement of said followers;

toward each other being adapted to urge saidi shoes into engagement with said friction portion.

7. A cushioning mechanism comprising a pair of relatively movable end followers, one of said followers having a longitudinally extending friction portion, friction shoes engaging said friction portion and being movable lengthwise thereof, said shoes having wedging surfaces on the outer sides thereof, spring means reacting between said last mentioned follower and said shoes for opposing said movement of said shoes, rubber means having one side thereof in engagement with said wedging surfaces on said shoes, the other of said followers having corresponding wedging surfaces engaging the other side of said rubber means, said rubber means upon relative movement of said followers bein-g adapted to urge said shoes longitudinally and laterally of said mechanism.

8. A cushioning mechanism comprising a fric- /tion member, friction shoes slidably associated with said member, spring means between said member and said shoes for opposing movement of said shoes along said member, said shoes being provided with sloping plane surfaces, follower means having plane surfaces sloped to correspond with said surfaces on said shoes, and rubber means interposed between said surfaces on said shoes and follower means, said vrubber means Yloe-- esami 7 ing compressible vto 'allow movement of said follower means toward said friction shoes and'being adapted to press said shoes into engagement with said friction member. y y I 9. A cushioning mechanism comprising afriction member, friction shoes sldably'engagin'g' said 'membeig spring means reacting between said member and said shoes for opposing movement of said shoes along said member, said shoes having sloping plane surfaces which converge toward the end of the mechanism, a follower member having plane surfaces substantially parallel to said surfaces on said shoes and in opposed relation thereto, and rubber means interposed between said opposing surfaces on 'saidshoe'siand follower member. A y

10. In av cushioning mechanism a friction member, friction shoes slidably a'ssocia'tedwith said member, spring means reacting between said member and said shoes for' opposing movement of said shoes along said member, a followermember associated with said shoes, said shoes and follower having correspondingly sloped opposed wedging surfaces, rubber means interposed between said shoes and follower member and being in engagement withsaid surfaces, saidr'ubber means being adapted to cushion movement of said follower lengthwise of said mechanism and to urge said shoes into engagement with said friction member, said follower member cornprising spaced tie walls at the sides' thereof adapted to engage said shoes'to limit movement of said follower relative to said shoes.

l1. In a cushioning mechanism a follower member having a pocket the walls of which are iiared outwardly, resilient pads received in said pocket and having one side in engagement with said flared walls, wedge-shaped members -in said pocket and engaging the other side of said pads, a friction member extending "into said pocket and slidably engaging said shoes, and spring means between said friction member and said shoes, said friction member being movable in a lengthwise direction relative to said shoes and follower member against the resistance of said 'pads and said spring means.

12. A cushioning mechanism comprising a central longitudinally extendingV friction member, wedge members engaging said friction member and slidable lengthwise thereof. spring means Ireacting directly between said wedge members and one end of said friction member for opposing movement of said wedge members relative to said friction member, said wedge members having outer surfaces converging toward an` en'd of said mechanism, a follower member having a pocket for receiving said wedge members, the walls 'of said pocket having corresponding converging plane surfaces spaced from the opposing sur-faces on said wedge members, and resilient pads interposed between said opposing surfaces in 'said pocket and on said wedge members.

13. A cushioning mechanism comprising a 'central friction member, a wedge member engaging an outer side of said friction member v'and being movable in a direction longitudinally thereof. spring means reacting between said' wedge member and said friction member for opposing said movement of said wedge member', a follower member associated with said wedge member, said follower member having a surface correspondingly sloped with a wedging vsurface on said wedge member, and rubber meansinterposed 'between said surfaces on said wedge member `and said follower member and being adapted tciirge said 8 wedge member laterally against said' friction member and also to cushion longitudinal movement of said follower relative to said shoe.

14. In aA cushioning mechanism, a friction member, friction shoes slidably associated' with said member, resilient means having its ends disposed between said shoes and an end of said friction member for opposing relative movement between said shoes and said member, and means for urging said shoes into frictional engagement with said member, said means comprising a follower member having a pair of V-shaped walls and rubber means interposed between said shoes and said walls.

15. In a cushioning mechanism a friction member, wedge-shaped members slidably associated with the outer sides of said member, spring vmeans reacting between said wedge members and said friction member for opposing movement of said wedge members relative to said friction member, follower means having a pair of sloping surfaces facing similarly sloped surfaces on said wedge members, and rubber means interposed between said surfaces on said wedge members and said follower means, said rubber means being adapted to urge said members into engagement with said friction member upon movement of said follower means lengthwise of said friction member.

16. In a cushioning mechanism a friction member, spring means adjacent said member, friction shoes at one end of said spring means in engagement with said member, said spring means reacting between said shoes and an end of said member, said shoes being adapted to move relative to said member against the resistance of said spring means, said shoes having exterior surfaces converging outwardly, follower means associated with said shoes and member and having interior surfaces diverging outwardly so as to correspond in slope to said surfaces on said shoes, rubber means interposed between said correspondingly sloped surfaces on said shoes and follower and adapted to resist movement of said follower relative to said shoes and to exert a lateral force against said shoes to urge them into increasing engagement with said member.

17. A cushioningy mechanism comprising a friction member, a friction Vshoe engaging said member and being movable lengthwise thereof, spring means having its ends reacting between an end of 'said friction member and said shoe, said shoe having; a wedge face, a resilient pad having one side thereof in engagement with said face and follower means having a wedge face engaging the other side of said pad and being adapted to subject said pad to combined compression and shear upon longitudinal movement of said wedge means relative to said shoe.

HUBERT L. SPENCE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,707,490 O'Connor Apr. 2, 1929 1,713,914 OConnor May 21, 1929 1,872,978 Krakau Aug. 23, 1932 1,956,108 Symington et al. Apr. 24, 1934 2,079,088 Spence May 4, 1937 2,211,463 Hobson Aug. 13, 1940 2,295,556 Flesch Sept. 1'5, 1942 2,336,969` Tack Dec.' 14, 1943 2,352,030 Spi'oil Junev 20, 1944 

